A process for producing enriched artificial rice

ABSTRACT

Enriched artificial rice is prepared by kneading together rice powder, nutrients (i.e. amino acids, vitamins, and/or minerals), water, and if desired, a binder (such as carboxymethylcellulose); steaming the mixture to semigelatinize the starch contained therein; granulating the resulting viscous product; and, if desired, coating the grains obtained.

O Umted States Patent [111 3,620,762

[72] Inventors Teruo Yolhlda [50] Field of Search 99/80, 83

Kanagawn-ken; Takaaki Sagan, Kanaga q TM [56] References Cited Ojma,Kanapwa-ken; Relji Takahnshl, UNITED STATES PATENTS K'MIWMWMMMTM2,831,770 4/1958 Antoshkiw 99/11 [21] A l N ggzyloglloflapan 2,879,1643/1959 White et a1. 99/14 pp o. 221 Filed June 24, 1969 OTHER REFERENCES[45] Patented Nov. 16, 1971 Kimura Chem1ca1 Abstracts vol. 52 17559,art1c|e en- [73] Assignee Ajnomotn Co., Inc. titled Artificial RiceTokyoJapau Bhatia et al., Food Manufacture Sept. 1956, pages 376- [32]Priority July 11, I968 380, page 377 relied upon {33] PrimaryExaminer-Raymond N. Jones [3 l 1 43/4868. Attorneyl(urt Kelman [54]PROCESS FOR PRODUCING ENRICHED ABSTRACT: Enriched artificial rice isprepared by kneading together rice powder, nutrients (i.e. amino acids,vitamins, and/or minerals), water, and if desired, a binder (such ascarboxymethyl-cellulose); steaming the mixture to semigelatinize thestarch contained therein; granulating the resulting viscous product;and, if desired, coating the grains obtained.

PROCESS FOR PRODUCING ENRICIED ARTIFICIAL RICE This invention relates toartificial rice, and particularly to a method of producing artificialrice.

Artificial rice produced by known processes can only contain about 3-l0percent of enriching materials. lts taste is bad and the quality ofcooked rice containing the artificial rice often becomes poor.

The primary object of the invention is a process for producinglow-priced and highly enriched artificial rice which does not turn brownby the Maillard reaction in spite of its high content of amino acids,forms good grains and has a taste not different from natural rice whenit is cooked mixed with natural rice.

The method of the invention comprises mixing rice powder with a suitableamount of enriching materials and, if desired a binder such ascarboxymethylcellulose, kneading the mixture with enough water to makethe water content 20-50 percent, heating the kneaded mixture with steamuntil the starch granules in the rice powder are partially gelatinized,forming the viscous intennediate product into grains on a suitablegranulator, and drying the grains with warm air at a temperature below80 C. to reduce their water content to 5l5 percent.

Suitable raw materials for the production of artificial rice accordingto the invention include natural rice of the type used for food but alsobroken rice or powdered rice that are not used for food.

These materials are crushed, if desired, soaked in a percent solution ora saturated solution of enriching materials such as amino acids forseveral minutes to several hours and shaped into dry grains by asuitable method.

During soaking, the enriching materials pass through the cell membraneof the rice and, as the water content of the rice is reduced suddenly bydrying the rice cells become brittle and break on account of a kind ofplasmolysis. Rice powder containing l0-l5 percent of the enrichingmaterials is obtained, through the content of enriching materialsdepends on the concentration of the solution in which the rice issoaked. Crushing is not necessary for rice powder; however, the processis very effective when natural rice grains are used.

Suitable enriching minerals include amino acids such as L- lysine,L-threonine, L- or DL-methionine and L- or DL-tryptophan, vitamins suchas thiamine, niacin and pyridoxin, and minerals such as calciumphosphate, calcium carbonate, potassium iodide and ferrous sulfate.These enriching materials especially amino acids, may be added in anamount to constitute up to 50 percent of solid matter in the artificialrice. Such a high concentration has not been achieved heretofore.

The powdered material mixed with enriching materials as described aboveis kneaded with water sufficient to make the water content 20-50percent. This is enough to semigelatinize the starch granules in therice powder.

Heating with steam is necessary to semigelatinize the starch granules inthe rice powder and a temperature of 90l20 C. is usually applied. If theheat treatment is more severe, the starch granules are expanded too muchand break. However, the conditions for semigelatinizing the rice starchobserved as strictly as is necessary with other types of starch (wheat,maize and so on).

The starch product obtained by steam heating is an intermediate of highviscosity which coats the enriching materials. The process makesgrain-forming easy and, prevents elution of enriching materials duringwashing with water.

The grains are formed on a granulator by known methods, for example theroller method (a press method) or the macaroni method. The resultinggrains are dried in warm air up to 80 C. fora suitable time until thewater content is reduced to 5-15 percent.

The enriched artificial rice produced according to the present processin white and has a lustrous surface, in spite of the high enrichmentwith amino acids and other nutrients, and the form of its grains is sosimilar to that of natural rice, that there is no significant differencefrom natural rice in appearance. When natural rice powder is used asmain raw material, forming is very easily accomplished without loss andis economically advantageous as compared to the use of starch or gluten.

The artificial rice may be coated if it is desired to be mixed withnatural rice and cooked after soaking in water for a long time.

The enriched artificial rice produced according to the present inventioncan have good hardness and elasticity, combined with a high content ofenriching nutrients and is also resistant to washing and soaking for along time when coated with a suitable film. Accordingly, this artificialrice can be mixed with natural rice before being cooked. When cooking isfinished, its grains are not broken and almost indistinguishable fromnatural rice in its appearance, viscosity, elasticity and taste.

EXAMPLE 1 In a solution containing 30 percent of L-lysine hydrochloridenatural rice was soaked for 10 hours and dried, whereby the rice grainsbecome very brittle. The L-lysine content of the rice afier beingcrushed mechanically was 10.7 percent. To 700 g. of the resulting ricepowder containing L- lysine, 140 g. of L-lysine hydrochloride, lOO g. ofL-threonine, 20 g. of calcium carbonate and 150 ml. of water were addedand the mixture was kneaded for 15 minutes. The starch in the ricepowder was semigelatinized by being steamed for 10-20 minutes, the steammaterial has formed into sheets (water content 27 percent) and formedinto grains in a double roller granulator. This forming was doneefficiently since the grains produced did not stick to the roller anddid not break.

The grains were screened and dried to a water content of 5 percent. Theobtained artificial rice could hardly be distinguished from natural ricein its appearance and color, it had a hardness of 15 g., and its tastewas good enough even when cooked with natural rice. An alcohol solutioncontaining 34 percent of shellac was sprinkled (30 ml. of the alcoholsolution and 5l5 g. of talc were used at one time) over the grains 'in apancoating machine, under warm air of 40-60 C. until the quantity ofshellac added amounted to g.

The coated artificial rice had a whiteness of 75 percent and a hardnessof 15 g. It contained 21 percent of L-lysine hydrochloride, 10 percentof L-threonine and 5 percent of water. The grains were rice shaped,their surface was smooth and had a desirable lustre, and this rice couldhardly be distinguished from natural rice in its appearance and tasteeven when cooked after being mixed with natural rice in an amount ofabout 1 percent.

EXAMPLE 2 750 g. of powder of nonglutinous rice which had passed througha IOO-mesh sieve and 210 g. of L-lysine hydrochloride were put into akneader and mixed well with stirring. After the mixture was kneaded with250 ml. of water for 15 minutes, its starch content was semigelatinizedby heating at C. for 30 minutes, and it was mixed well with 80 g. of asolution containing 10 percent of carboxymethylcellulose. The resultingmixture was put into a macaroni-form granulator and formed intorice-shaped grains which were dried to a water content below 5 percent.

The obtained rice grains could hardly be distinguished from natural ricein their appearance and had a hardness of 8 g. This artificial rice wascoated by being sprayed with an alcohol solution containing 10 percentof shellac in a pancoating machine for 4 hours.

When the coated artificial rice was washed with water and cooked afterbeing mixed with natural rice in an amount of 1 percent, it lost verylittle of its amino acids upon washing, and the appearance and taste ofthe cooked rice could hardly be distinguished from natural rice.

What we claim is:

l. A method of producing artificial rice which comprises:

a. kneading a mixture of powdered rice with at least one nutrient aminoacid and with an amount of water sufficient to make the water content ofthe resulting mixture to 50 percent, whereby a paste is produced.

1. The amino acid content of said mixture being 15 to 50 percent of theweight of solids in said mixture;

b. exposing said paste to steam for a time and at a temperaturesufficient to semigelatinize the starch and said powdered rice;

c. shaping the paste containing said semigelatinized starch into grains;and

d. drying said grains to a water content of not more than 15 percent.

2. A method as set forth in claim 1 wherein said paste is exposed tosaid steam at to C.

3. A method as set forth in claim 2 wherein said amino acid contentincludes at least one member of the group consisting of L-lysine,L-threonine L-methioninc, DL-methionine, L- tryptophan, andDL-tryptophan.

4. A method as set forth in claim 2, wherein said at least one aminoacid is a member of the group consisting of L-lysine, L- threonine,L-methionine, DL-methionine, L-tryptophan, and DL-tryptophan.

5. A method as set forth in claim 4 wherein said grains are dried to awater content not substantially smaller than 5 percent.

l i 1 I i

2. A method as set forth in claim 1 wherein said paste is exposed tosaid steam at 90* to 120* C.
 3. A method as set forth in claim 2 whereinsaid amino acid content includes at least one member of the groupconsisting of L-lysine, L-threonine L-methionine, DL-methionine,L-tryptophan, and DL-tryptophan.
 4. A method as set forth in claim 2,wherein said at least one amino acid is a member of the group consistingof L-lysine, L-threonine, L-methionine, DL-methionine, L-tryptophan, andDL-tryptophan.
 5. A method as set forth in claim 4 wherein said grainsare dried to a water content not substantially smaller than 5 percent.